diff --git a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiStreamFunctionCallingHelper.java b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiStreamFunctionCallingHelper.java
index e159d0362c9..96c43655d3f 100644
--- a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiStreamFunctionCallingHelper.java
+++ b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiStreamFunctionCallingHelper.java
@@ -110,7 +110,7 @@ private ChatCompletionMessage merge(ChatCompletionMessage previous, ChatCompleti
 				toolCalls.addAll(previous.toolCalls().subList(0, previous.toolCalls().size() - 1));
 			}
 		}
-		if (current.toolCalls() != null) {
+		if (current.toolCalls() != null && current.toolCalls().size() > 0) {
 			if (current.toolCalls().size() > 1) {
 				throw new IllegalStateException("Currently only one tool call is supported per message!");
 			}